From 647d23267694b69050816c1c438f3b2768ef6bcc Mon Sep 17 00:00:00 2001
From: Alexander Ebert <ebert@woltlab.com>
Date: Sun, 7 Jul 2013 20:48:13 +0200
Subject: [PATCH] Forcing JavaScript to be inserted on the page bottom

---
 .../files/lib/util/HeaderUtil.class.php       | 78 ++++++++++++-------
 1 file changed, 50 insertions(+), 28 deletions(-)

diff --git a/wcfsetup/install/files/lib/util/HeaderUtil.class.php b/wcfsetup/install/files/lib/util/HeaderUtil.class.php
index 2b14c96178..f61365be4d 100644
--- a/wcfsetup/install/files/lib/util/HeaderUtil.class.php
+++ b/wcfsetup/install/files/lib/util/HeaderUtil.class.php
@@ -1,6 +1,7 @@
 <?php
 namespace wcf\util;
 use wcf\system\application\ApplicationHandler;
+use wcf\system\event\EventHandler;
 use wcf\system\request\RouteHandler;
 use wcf\system\WCF;
 
@@ -15,6 +16,12 @@ use wcf\system\WCF;
  * @category	Community Framework
  */
 final class HeaderUtil {
+	/**
+	 * output HTML
+	 * @var	string
+	 */
+	public static $output = '';
+	
 	/**
 	 * Alias to php setcookie() function.
 	 */
@@ -37,10 +44,7 @@ final class HeaderUtil {
 			self::sendNoCacheHeaders();
 		}
 		
-		// enable gzip compression
-		if (HTTP_ENABLE_GZIP && HTTP_GZIP_LEVEL > 0 && HTTP_GZIP_LEVEL < 10 && !defined('HTTP_DISABLE_GZIP')) {
-			self::compressOutput();
-		}
+		ob_start(array('wcf\util\HeaderUtil', 'parseOutput'));
 		
 		// send Internet Explorer compatibility mode
 		@header('X-UA-Compatible: IE=edge');
@@ -57,34 +61,52 @@ final class HeaderUtil {
 	}
 	
 	/**
-	 * Enables the gzip compression of the page output.
+	 * Parses the rendered output.
+	 * 
+	 * @param	string		$output
+	 * @return	string
 	 */
-	public static function compressOutput() {
-		if (function_exists('gzcompress') && !@ini_get('zlib.output_compression') && !@ini_get('output_handler') && isset($_SERVER['HTTP_ACCEPT_ENCODING']) && strstr($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip')) {
-			if (strstr($_SERVER['HTTP_ACCEPT_ENCODING'], 'x-gzip')) {
-				@header('Content-Encoding: x-gzip');
-			}
-			else {
-				@header('Content-Encoding: gzip');
+	public static function parseOutput($output) {
+		self::$output = $output;
+		
+		// move script tags to the bottom of the page
+		$javascript = array();
+		self::$output = preg_replace_callback('~<script(.*?)</script>~s', function($matches) use (&$javascript) {
+			$javascript[] = $matches[0];
+			return '';
+		}, self::$output);
+		
+		self::$output = str_replace(array('</body>', '</html>'), array('', ''), self::$output);
+		self::$output .= "\n".implode("\n", $javascript)."\n</body></html>";
+		
+		// 3rd party plugins may differ the actual output before it is sent to the browser
+		// please be aware, that $eventObj is not available here due to this being a static
+		// class. Use HeaderUtil::$output to modify it.
+		EventHandler::getInstance()->fireAction('wcf\util\HeaderUtil', 'parseOutput');
+		
+		// enable gzip compression
+		if (HTTP_ENABLE_GZIP && HTTP_GZIP_LEVEL > 0 && HTTP_GZIP_LEVEL < 10 && !defined('HTTP_DISABLE_GZIP')) {
+			if (function_exists('gzcompress') && !@ini_get('zlib.output_compression') && !@ini_get('output_handler') && isset($_SERVER['HTTP_ACCEPT_ENCODING']) && strstr($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip')) {
+				if (strstr($_SERVER['HTTP_ACCEPT_ENCODING'], 'x-gzip')) {
+					@header('Content-Encoding: x-gzip');
+				}
+				else {
+					@header('Content-Encoding: gzip');
+				}
+				
+				$size = strlen(self::$output);
+				$crc = crc32(self::$output);
+				
+				$newOutput = "\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\xff";
+				$newOutput .= substr(gzcompress(self::$output, HTTP_GZIP_LEVEL), 2, -4);
+				$newOutput .= pack('V', $crc);
+				$newOutput .= pack('V', $size);
+				
+				self::$output = $newOutput;
 			}
-			ob_start(array('wcf\util\HeaderUtil', 'getCompressedOutput'));
 		}
-	}
-	
-	/**
-	 * Outputs the compressed page content.
-	 */
-	public static function getCompressedOutput($output) {
-		$size = strlen($output);
-		$crc = crc32($output);
-		
-		$newOutput = "\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\xff";
-		$newOutput .= substr(gzcompress($output, HTTP_GZIP_LEVEL), 2, -4);
-		unset($output);
-		$newOutput .= pack('V', $crc);
-		$newOutput .= pack('V', $size);
 		
-		return $newOutput;
+		return self::$output;
 	}
 	
 	/**
-- 
2.20.1